win-screenshot

Capture screenshots on Windows using PowerShell and .NET System.Drawing. No external dependencies — uses built-in Windows APIs.

Pair with OpenClaw's image tool to analyze captured screenshots.

Full Screen Capture

powershell

powershell.exe -NoProfile -Command "
Add-Type -AssemblyName System.Windows.Forms
Add-Type -AssemblyName System.Drawing
$screen = [System.Windows.Forms.Screen]::PrimaryScreen.Bounds
$bmp = New-Object System.Drawing.Bitmap($screen.Width, $screen.Height)
$g = [System.Drawing.Graphics]::FromImage($bmp)
$g.CopyFromScreen($screen.Location, [System.Drawing.Point]::Empty, $screen.Size)
$bmp.Save('OUTPUT_PATH', [System.Drawing.Imaging.ImageFormat]::Png)
$g.Dispose(); $bmp.Dispose()
Write-Host 'Saved to OUTPUT_PATH'
"

Replace OUTPUT_PATH with the desired file path (e.g., $env:TEMP\screenshot.png).

Region Capture

Capture a specific rectangular area (x, y, width, height):

powershell

powershell.exe -NoProfile -Command "
Add-Type -AssemblyName System.Drawing
$bmp = New-Object System.Drawing.Bitmap(WIDTH, HEIGHT)
$g = [System.Drawing.Graphics]::FromImage($bmp)
$g.CopyFromScreen(X, Y, 0, 0, [System.Drawing.Size]::new(WIDTH, HEIGHT))
$bmp.Save('OUTPUT_PATH', [System.Drawing.Imaging.ImageFormat]::Png)
$g.Dispose(); $bmp.Dispose()
"

Replace X, Y, WIDTH, HEIGHT with pixel coordinates.

Multi-Monitor (All Screens)

powershell

powershell.exe -NoProfile -Command "
Add-Type -AssemblyName System.Windows.Forms
Add-Type -AssemblyName System.Drawing
$bounds = [System.Windows.Forms.SystemInformation]::VirtualScreen
$bmp = New-Object System.Drawing.Bitmap($bounds.Width, $bounds.Height)
$g = [System.Drawing.Graphics]::FromImage($bmp)
$g.CopyFromScreen($bounds.Location, [System.Drawing.Point]::Empty, $bounds.Size)
$bmp.Save('OUTPUT_PATH', [System.Drawing.Imaging.ImageFormat]::Png)
$g.Dispose(); $bmp.Dispose()
"

List Visible Windows

List all visible windows with titles and dimensions (useful before targeted capture):

powershell

powershell.exe -NoProfile -Command "
Add-Type @'
using System;
using System.Runtime.InteropServices;
using System.Text;
public class WinAPI {
    [DllImport(\"user32.dll\")] public static extern bool EnumWindows(EnumWindowsProc lpEnumFunc, IntPtr lParam);
    [DllImport(\"user32.dll\")] public static extern int GetWindowText(IntPtr hWnd, StringBuilder lpString, int nMaxCount);
    [DllImport(\"user32.dll\")] public static extern bool IsWindowVisible(IntPtr hWnd);
    [DllImport(\"user32.dll\")] public static extern bool GetWindowRect(IntPtr hWnd, out RECT lpRect);
    public delegate bool EnumWindowsProc(IntPtr hWnd, IntPtr lParam);
    [StructLayout(LayoutKind.Sequential)] public struct RECT { public int Left, Top, Right, Bottom; }
}
'@
[WinAPI]::EnumWindows({
    param(`$hWnd, `$lParam)
    if ([WinAPI]::IsWindowVisible(`$hWnd)) {
        `$sb = New-Object System.Text.StringBuilder(256)
        [WinAPI]::GetWindowText(`$hWnd, `$sb, 256) | Out-Null
        `$title = `$sb.ToString()
        if (`$title.Length -gt 0) {
            `$rect = New-Object WinAPI+RECT
            [WinAPI]::GetWindowRect(`$hWnd, [ref]`$rect) | Out-Null
            `$w = `$rect.Right - `$rect.Left; `$h = `$rect.Bottom - `$rect.Top
            Write-Host \"`$title | `$(`$rect.Left),`$(`$rect.Top) `${w}x`${h}\"
        }
    }
    return `$true
}, [IntPtr]::Zero) | Out-Null
"

Capture Specific Window by Title

Use region capture with coordinates from the window list:

powershell

powershell.exe -NoProfile -Command "
Add-Type -AssemblyName System.Drawing
Add-Type @'
using System;
using System.Runtime.InteropServices;
using System.Text;
public class WinFind {
    [DllImport(\"user32.dll\")] public static extern IntPtr FindWindow(string lpClassName, string lpWindowName);
    [DllImport(\"user32.dll\")] public static extern bool GetWindowRect(IntPtr hWnd, out RECT lpRect);
    [StructLayout(LayoutKind.Sequential)] public struct RECT { public int Left, Top, Right, Bottom; }
}
'@
`$hWnd = [WinFind]::FindWindow(`$null, 'WINDOW_TITLE')
if (`$hWnd -eq [IntPtr]::Zero) { Write-Host 'Window not found'; exit 1 }
`$rect = New-Object WinFind+RECT
[WinFind]::GetWindowRect(`$hWnd, [ref]`$rect) | Out-Null
`$w = `$rect.Right - `$rect.Left; `$h = `$rect.Bottom - `$rect.Top
`$bmp = New-Object System.Drawing.Bitmap(`$w, `$h)
`$g = [System.Drawing.Graphics]::FromImage(`$bmp)
`$g.CopyFromScreen(`$rect.Left, `$rect.Top, 0, 0, [System.Drawing.Size]::new(`$w, `$h))
`$bmp.Save('OUTPUT_PATH', [System.Drawing.Imaging.ImageFormat]::Png)
`$g.Dispose(); `$bmp.Dispose()
Write-Host \"Captured window: `${w}x`${h}\"
"

Replace WINDOW_TITLE with the exact window title from the window list.

Recommended Workflow

•List windows to find the target
•Capture (full screen, region, or window)
•Use OpenClaw's image tool to analyze the screenshot

code

win-screenshot (capture) → image tool (analyze) → agent acts on result

Notes

•Works on Windows 10/11 with PowerShell 5.1+.
•No external dependencies — uses built-in .NET Framework assemblies.
•Output format: PNG (lossless). Change ImageFormat::Png to Jpeg for smaller files.
•For WSL: call powershell.exe from within WSL; save to a Windows-accessible path.
•DPI scaling: captured resolution matches the actual screen pixels.
•Window capture uses screen coordinates — it captures what's visible (may include overlapping windows).
•Default save location suggestion: $env:TEMP\pcclaw-screenshot.png.